Sulfonic Acid Ester Electrolyte for Battery Cycle Life
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional nonaqueous electrolyte batteries face challenges in achieving high capacity, high-temperature storage characteristics, and cycle life due to side reactions with the electrolyte, leading to capacity deterioration and gas evolution, which existing additives fail to adequately address simultaneously.
Innovation Solution
A nonaqueous electrolyte solution containing a specific sulfonic acid ester with an unsaturated bond, combined with fluorine atom-containing cyclic carbonates and other compounds, is used to form a stable film on electrodes, inhibiting side reactions and gas evolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If conventional additives (vinylene carbonate, alkyl alkanesulfonate, alkynyl alkanesulfonate, or dialkylsulfonic acid ester) are used to form protective films on electrodes, then charge/discharge cycle life is enhanced, but high-temperature storage characteristics and capacity retention are insufficient due to side reactions
Solution Approach 1:
The invention changes the chemical parameters of the additive by specifying a sulfonic acid ester with particular structural features (formula 1 with specific R, L, and Z group definitions). This structural modification enables the additive to form a protective film that is stable at high temperatures, simultaneously improving both cycle life and storage characteristics without the side reactions that plague conventional additives.
Solution Approach 2:
The invention uses a composite approach by combining the sulfonic acid ester additive with specific nonaqueous solvents (cyclic carbonates, chain carbonates, carboxylic acid esters) and lithium salts. This composite electrolyte system creates a synergistic effect where the sulfonic acid ester forms a stable protective film while the solvent system maintains high-temperature stability, resolving the contradiction between cycle life enhancement and storage characteristics.
2Quantity of substance
If the active material layer of the electrode is pressurized to increase density and capacity, then energy density increases, but uniform utilization of active material deteriorates and lithium precipitation occurs
Solution Approach 1:
The sulfonic acid ester additive acts as an intermediary that forms a protective film on the electrode surface. This film mediates between the pressurized active material layer and the electrolyte, enabling uniform lithium ion transport even at high densities. The protective film prevents direct harmful interactions while maintaining ion permeability, thus allowing high energy density without lithium precipitation or non-uniform reactions.
3Quantity of substance
If the use range of the positive electrode is expanded to high potential to increase capacity, then energy density increases, but the positive electrode becomes more active and deterioration accelerates due to reactions with the electrolyte solution
Solution Approach 1:
The sulfonic acid ester additive performs preliminary anti-action by forming a stable protective film on the positive electrode surface before harmful reactions can occur. This pre-formed film acts as a barrier that prevents the highly active positive electrode (operating at expanded potential ranges) from reacting with the electrolyte, thus enabling high-capacity operation without accelerated deterioration.
4Quantity of substance
If battery capacity is increased leading to decreased internal space, then energy density increases, but internal pressure significantly increases even with small gas evolution from electrolyte decomposition
Solution Approach 1:
The invention converts the potential harm of gas evolution into a benefit by using the sulfonic acid ester additive to suppress gas-forming side reactions. The additive transforms the electrolyte system into one that minimizes gas generation, thereby allowing high-capacity batteries with reduced internal volume to maintain acceptable internal pressure levels despite the constrained space for gas accommodation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution significantly enhances battery storage characteristics and cycle life by reducing capacity deterioration and gas evolution during high-temperature storage, while maintaining battery performance.
Implementation Method 1
a nonaqueous electrolyte solution containing a sulfonic acid ester with an unsaturated bond... to form a stable film on electrodes, inhibiting side reactions
Implementation Method 2
a sulfonic acid ester with an unsaturated bond... significantly enhances battery storage characteristics and cycle life by reducing capacity deterioration
Data Source
AI summary
The present invention relates to a nonaqueous electrolyte solution comprising a lithium salt and a nonaqueous organic solvent, wherein the nonaqueous electrolyte solution comprises a specific sulfonic acid ester.